Gain Scheduling Control of Nonlinear Shock Motion Based on Equilibrium Manifold Linearization Model

The equilibrium manifold linearization model of nonlinear shock motion is of higher accuracy and lower complexity over other models such as the small perturbation model and the piecewise-linear model. This paper analyzes the physical significance of the equilibrium manifold linearization model, and the self-feedback mechanism of shock motion is revealed. This helps to describe the stability and dynamics of shock motion. Based on the model, the paper puts forwards a gain scheduling control method for nonlinear shock motion. Simulation has shown the validity of the control scheme.

Motion stability and control of supercavitating vehicle with variable cavitation number

Cavitation number and speed are capable of variation during the motion of supercavitating vehicle underwater,for example,under the condition of accelerated motion stage and external disturbance.The dynamic model and control challenge associated with the longitudinal motion of supercavitating vehicle with variable cavitation number and speed have been explored.Based on the principle of cavity expansion independence the properties of cavity and the influence on planning force of body were researched.Calculation formula of efficiency of the fin was presented.Nonlinear dynamics model of variable cavitation number and speed supercavitating vehicle was established.Stabilities of the open-loop systems of different situations were analyzed.The simulations results of open-loop systems show that it is necessary to design a control method to control a supercavitating vehicle.A gain schedule controller with guaranteed H∞ performance was designed to stabilize the dive-plane dynamics of supercavitating vehicle under changing conditions.

MULTITASK SCHEDULING IN NETWORKED CONTROL SYSTEMS WITH APPLICATION TO LARGE SCALE VEHICLE CONTROL

Aiming at scheduling problems of networked control system （NCS） used to fulfill motion synthesis and cooperation control of the distributed multi-mechatronic systems, the differences of network scheduling and task scheduling are compared, and the mathematic description of task scheduling is presented. A performance index function of task scheduling of NCS according to task balance and traffic load matching principles is defined. According to this index, a static scheduling method is designed and implemented to controlling task set simulation of the DCY100 transportation vehicle. The simulation results are applied successfully to practical engineering in this case so as to validate the effectiveness of the proposed performance index and scheduling algorithm.

Missile robust gain scheduling autopilot design using full block multipliers

Reduction of conservatism is one of the key and difficult problems in missile robust gain scheduling autopilot design based on multipliers.This article presents a scheme of adopting linear parameter-varying（LPV） control approach with full block multipliers to design a missile robust gain scheduling autopilot in order to eliminate conservatism.A model matching design structure with a high demand on matching precision is constructed based on the missile linear fractional transformation（LFT） model.By applying full block S-procedure and elimination lemma,a convex feasibility problem with an infinite number of constraints is formulated to satisfy robust quadratic performance specifications.Then a grid method is adopted to transform the infinite-dimensional convex feasibility problem into a solvable finite-dimensional convex feasibility problem,based on which a gain scheduling controller with linear fractional dependence on the flight Mach number and altitude is derived.Static and dynamic simulation results show the effectiveness and feasibility of the proposed scheme.

Designing method of acceleration and deceleration control schedule for variable cycle engine

Studies show that different geometries of a Variable Cycle Engine(VCE)can be adjusted during the transient stage of the engine operation to improve the engine performance.However,this improvement increases the complexity of the acceleration and deceleration control schedule.In order to resolve this problem,the Transient-state Reverse Method(TRM)is established in the present study based on the Steady-state Reverse Method(SRM)and the Virtual Power Extraction Method(VPEM).The state factors in the component-based engine performance models are replaced by variable geometry parameters to establish the TRM for a double bypass VCE.Obtained results are compared with the conventional component-based model from different aspects,including the accuracy and the convergence rate.The TRM is then employed to optimize the control schedule of a VCE.Obtained results show that the accuracy and the convergence rate of the proposed method are consistent with that of the conventional model.On the other hand,it is found that the new-model-optimized control schedules reduce the acceleration and deceleration time by 45%and 54%,respectively.Meanwhile,the surge margin of compressors,fuel–air ratio and the turbine inlet temperature maintained are within the acceptable criteria.It is concluded that the proposed TRM is a powerful method to design the acceleration and deceleration control schedule of the VCE.

End-to-End Utilization Control for Aperiodic Tasks in Distributed Real-Time Systems

An increasing number of DRTS （Distributed model. The key challenges of such DRTS are guaranteeing Real-Time Systems） are employing an end-to-end aperiodic task utilization on multiple processors to achieve overload protection, and meeting the end-to-end deadlines of aperiodic tasks. This paper proposes an end-to-end utilization control architecture and an IC-EAT （Integration Control for End-to-End Aperiodic Tasks） algorithm, which features a distributed feedback loop that dynamically enforces the desired utilization bound on multiple processors. IC-EAT integrates admission control with feedback control, which is able to dynamically determine the QoS （Quality of Service） of incoming tasks and guarantee the end-to-end deadlines of admitted tasks. Then an LQOCM （Linear Quadratic Optimal Control Model） is presented. Finally, experiments demonstrate that, for the end-to-end DRTS whose control matrix G falls into the stable region, the IC-EAT is convergent and stable. Moreover,it is capable of providing better QoS guarantees for end-to-end aperiodic tasks and improving the system throughput.

Design method of optimal control schedule for the adaptive cycle engine steady-state performance

The alternative working modes and flexible working states are the outstanding features of an adaptive cycle engine, with a proper control schedule design being the only way to exploit the performance of such an engine. However, unreasonable design in the control schedule causes not only performance deterioration but also serious aerodynamic stability problems. Thus, in this work,a hybrid optimization method that automatically chooses the working modes and identifies the optimal and smooth control schedules is proposed, by combining the differential evolution algorithm and the Latin hypercube sampling method. The control schedule architecture does not only optimize the engine steady-state performance under different working modes but also solves the control-schedule discontinuity problem, especially during mode transition. The optimal control schedules are continuous and almost monotonic, and hence are strongly suitable for a control system, and are designed for two different working conditions, i.e., supersonic and subsonic throttling,which proves that the proposed hybrid method applies to various working conditions. The evaluation demonstrates that the proposed control method optimizes the engine performance, the surge margin of the compression components, and the range of the thrust during throttling.

Efective Object Identification and Association by Varying Coverage Through RFID Power Control

This paper presents an effective power scheduling strategy for energy efficient multiple objects identification and association. The proposed method can be utilized in many heterogeneous surveillance systems with visual sensors and RFID （radio-frequency identification） readers where energy efficiency as well as association rate are critical Multiple objects positions and trajectory estimates are used to decide the power level of RFID readers. Several key parameters including the time windows and the distance separations are defined in the method in order to minimize the effects of RFID coverage uncertainty. The power cost model is defined and incorporated into the method to minimize energy consumption and to maximize association performance. The proposed method computes the power cost using the range of the outermost position for possible single association and group associations at every sampling time. An RFID reader is activated with the proper coverage range when the power cost for the current time is lower than the power cost for the next time sample. The simplicity of the power cost model relieves the problematic combinatorial comparisons in multiple object cases. The performance comparison simulation with the minimum and maximum energy consumption shows that the proposed method achieves fast single associations with less energy consumption. Finally, the realistic comparison simulation with the fixed range RFID readers demonstrates that the proposed method outperforms the fixed ranges in terms of single association rate and energy consumption.